Dyeable polyolefins



United States Patent 3,299,030 DYEABLE POLYOLEFINS Albin F. Turbak,Danville, Ill., and Allen Noshay, East Brunswick, and Gabriel Karoly,Elizabeth, N.J., assignors to Esso Research and Engineering Company, acorporation of Delaware No Drawing. Filed Aug. 22, 1963, Ser. No.303,916

7 Claims. (Cl. 260--93.7)

This invention relates to a process for treating alphaolefin polymers torender them dyeable, and the composition produced thereby.

Poly alpha-olefin polymers have found increasing interest as textilefibers and 'materials because of their desirable properties of strengthand low cost. One of the more difficult problems encountered, however,has been the poor dye acceptance of such fibers because of the inertnessof a hydrocarbon polymer. Although a poly alpha-olefin material, such aspolypropylene, can be dyed, its fastness to typical textile environmentshas been inadequate.

It has now been found that the receptivity of alphaolefin polymers todyeing may be improved by blending the polymer with 0.1 to 20.0 weightpercent, preferably 0.2 to 5.0 weight percent, of a nickel derivative ofa specific class of amino acids. The polymer may then be spun intofibers and contacted with dyes. By means of this treatment, not only isthe dye uptake of the polymer improved, but more importantly, theresistance of the dyed product to light, washing, and dry cleaning isimproved.

An additional and very important advantage of these nickel-amino acidsubstances is that when the polymer which has been blended with thesematerials is spun into filaments at high temperature and pressure, theresulting fiber is white.

The fiber does not discolor at such extreme conditions of temperatureand pressure because these particular nickel-amino acid substances donot react with the phenolcontaining or sulfur-containing stabilizerswhich are often conventionally dispersed in the hot polymer mix. Thesestabilizers are generally present in amounts of between about 0.1 to 1.0weight percent of the polymer. They often are used together. See forexample Industrial & Engineering Chemistry, volume 1, No. 4, pp. 236 etseq. Some examples of these stabilizing agents which contain sulfur are:di-tert-octyl trisulfide, di-tert-octyl tetrasulfide,dilaurylthiodipropionate, the esters of polysulfides derived fromfl-mercaptopropionic acid, and zinc dibutyl dithiocarbamate. Someexamples of phenolic stabilizing agents are: N-lauroyl p-amino phenol;4,4'-methylene bis(2,6- ditertiary butyl phenol); 4,4-benzylidenebis(2,6-ditertiary butyl phenol); 2-hydroxy, 4-methoxy benzophenone;2-hydroxy, 4-octoxy benzophenone; dipinenediphenol; 4,4'-isobutylidenebisphenol; 3-methyl, 6-t-butyl phenol and 4-methyl, 2,6-di-tbutylphenol. The advantage of producing a white fiber is obvious tothose skilled in the art. Discoloration in a fiber not only limits itsuse to dyed fabrics but also interferes with the proper dyeing of thetextile produced therefrom, since muddy, dull, and impure hues areproduced.

While this invention is principally directed to the dyeing of fibers orfilaments, it may also be used to dye poly alpha-olefin films, foils,and other formed products.

The polymers treated by the process of the invention are alpha-olefinhomopolymers and copolymers. The alpha-olefin homopolymer can beprepared by any known process, such as the so-called Ziegler process,see for example Belgian Patent 533,362 and Belgian Patent 538,782.Examples of homopolymers within the scope of the invention includepolyethylene, polypropylene, poly 1- butene and poly l-heptene. Polymersor copolymers of 3,299,030 Patented Jan. 17, 1967 branched chainalpha-olefins where the branching occurs no closer than the third carbonatom can also be employed such as poly 4,4-dimethyl-1-pentene, poly 4-methyl-l-pentene and poly 3-methyl-1-butene. In general, thehomopolymers are prepared from alpha-olefins having from 2 to 12 carbonatoms. The copolymers employed in the process of the invention includecopolymers of two different alpha-olefins such as ethylene-propylenecopolymers, ethylene-l-hexene copolymers and alphaolfin-aromatic olefincopolymers containing from 1 to 15% by weight of an aromatic olefin,such as for example copolymers of styrene and 4-methyl-1-pentene. Also,blends of one or more of the previously mentioned polymers can beemployed. The polymers and copolymers employed in the invention haveviscosity average molecular weights ranging from 100,000 to 1,000,000.The preferred polymers and copolymers of the invention are thoseprepared by the use of alkyl metal catalysts. Most preferred ispolypropylene. Catalysts which are useful in this process are mixturesof reducible heavy transition metal compounds and reducing metalcontaining substances, or mixtures of partially reduced heavy transitionmetal compounds and organometallic activators. Examples of thesecatalysts are The catalysts used for preparing the preferred polymersemployed in the instant process are those catalysts given on page 6,line 20 to page 10, line 21 of copending application Serial No. 831,210,filed August 3, 1959, now abandoned.

The nickel-amino acid derivatives of this invention can be prepared byreacting the amino acid with a nickel salt, preferably nickel chloride,in methanol, diluting with an equal volume of water, and precipitatingthe desired product from solution by adjusting the .pH to about 7 withcaustic. Elemental analysis indicates that a complex thereby formshaving the following general structure: [amino acidhNi'ZH- O. About 1mole of nickel halide can be reacted with 1 to 3 moles of amino acid,although it is preferred to use 1 mole of nickel halide to 2 moles ofamino acid.

The amino acids of this invention are organic car-boxylic acids having aprimary or secondary amino group in a position alpha to the carboxylgroup. They may be represented by the formula where R and R aresubstituted and unsubstituted alkyl,

scription have been found to be unsuitable for the pres-.

ent invention. Thus, for example, a blend of the polymer with the nickelcomplex or derivative of ,B-alanine could not be spun into fibers; ablend with the nickel derivative of picolinic acid could be spun intofibers but would not accept dyes; and a blend with nickelN-lauryl-B-imino dipropionate formed unsatisfactory green coloredfibers.

The dyes which are useful in this invention are chelatable dyes. Theseinclude the National Polypropylene series of dyes produced by theNational Aniline Company. Examples of these are Violet 3BR, Green B,Brilliant Blue B and Brilliant Orange R. Also useful are ortho hydroxyazo dyes generally. These dyes include monoazo dyes, conjugated diandmulti-azo dyes as well as azo pyrazolone, o,o-dihydroxy azo, ando-hydroxy-o-carboxy azo type dyes. Examples of these are Orasol Yellow3G (Solvent Yellow 17), Sudan Orange RRA (Solvent Orange 7), Sudan Red4BA (Oil Red 24), and Oil Red (Solvent Red 27).

The polymer blend which has been melt spun or extruded into fibers ormolded objects is contacted with the aqueous dye bath. In general thedye baths employed contain from 0.1 to weight percent of dye based onthe weight of the goods to be dyed. The temperature of dyeing and thetime of immersion depend on the proportion of nickel compound in theblend, the particular nickel derivative employed, the concentration ofdye employed, and the intensity of color desired. These parameters caneasily be determined by routine experimentation. The temperature ofdyeing is not critical although the dye bath is usually maintained atthe boiling point.

This invention will be more fully understood by reference to thefollowing examples.

EXAMPLE 1 A polypropylene polymer was formed by passing propylene gasinto a dispersion containing Al(Et) and TiC1 in an aromatic diluent at atemperature of 80 C.

Hydrogen was used to control the molecular weight. A crystallinepolypropylene resulted having an intrinsic viscosity of 1.5 (in tetralinat 120 C.) and a melt index of 20. This polymer was blended with 0.5weight percent of each of 2-hydroxy, 4-octoxy benzophenone anddilaurylthiodipropionate and then spun into fibers by methods known inthe art. When these fibers were contacted with the dyes suitable forthis invention such as the National Polypropylene dyes and Orasol Yellow36, essentially no dye pickup and retention were observed.

EXAMPLE 2 A nickel derivative of D,L-alanine (racemic mixture ofa-alanine) was prepared specifically as follows: 0.5 mole of D,L-alanineand 0.25 mole of NiCl -6H O were stirred in a mixture of 750 ml.methanol and 375 m1. H O. Stirring was continued for minutes, whileheating gently on a steam bath. The reaction product was soluble. The pHof the solution was adjusted to 7 with 50% aqueous NaOH. The resultinglight blue precipitate was filtered and dried in a vacuum oven at 55 C.The yield was 48.8 gms. Analysis found: C, 26.56; H, 5.91; N, 10.73; Ni,22.31. Calculated for C, 26.6; H, 5.9; N, 10.3; Ni, 21.5.

0.5 weight percent of this derivative was blended with the stabilizedpolypropylene powder of Example 1 by mixing in a Waring Blendor andextruding and pelletizing in a Brabender extruder at 500 F.

This blend was spun at 580 F. in a continuous spinning unit into 165/34multifilaments which were then drawn at a 3.8/1 ratio. The fibersobtained had 3.0 g.p.d. tenacity and 62% elongation, and they wereoptically white.

The resulting fibers were contacted with National Aniline PolypropyleneGreen B, Violet 3BR, and Brilliant Orange R, as follows: The dyeingswere carried out in water at 95 C. for 1 hour in dye baths containing 1weight percent dyestulf and 0.5 weight percent nonionic (Igepal)surfactant. The fibers dyed We l with all three dyestuffs.

4 The dyed fibers were examined according to the AATCC test procedures,and found to have a rating of 5 for wash, dry cleaning and lightfastness.

EXAMPLE 3 The nickel derivative of D,L-tyrosine was prepared under thesame conditions as used in Example 2 for D,L- alanine. Stabilizedpolypropylene of Example 1 was blended with 0.5 weight percent of thenickel derivative of tyrosine in a Waring Blendor, extruded into pelletsand spun into /34 multifilaments. The white fiber obtained had 3.65g.p.d. tenacity and 38% elongation. It was dyed with the NationalPolypropylene dyes listed in Example 2. These dyeings also displayedgood dyeability and fastness properties.

EXAMPLE 4 The nickel derivative of D,L-leucine was prepared under thesame conditions as used in Example 2 for D,L- alanine. Stabilizedpolypropylene of Example 1 was blended with 1.0 weight percent of thenickel derivatives of leucine in a Waring Blendor, extruded into pelletsand spun into 165/34 multifilaments. The white fiber obtained had 3.67g.p.d. tenacity and 38% elongation. It was dyed with the NationalPolypropylene dyes listed in Example 2. These dyeings also displayedgood dyeability and fastness properties.

EXAMPLE 5 Example 2 was repeated with the exception that ,8- alanine wasused instead of D,L-alanine (an alpha amino acid). Satisfactory fiberscould not be spun from the blend with stabilized polypropylene owing tothe formation of gas during spinning which caused bubbles in the fiberand led to excessive breakage even when the take-up speed was kept low.

This invention has been described in connection with certain specificembodiments thereof; however, it should be understood that these are byway of example rather than by way of limitation, and it is not intendedthat the invention be restricted thereby.

What is claimed is:

1. A dyeable composition of matter comprising a polymer of a hydrocarbonalpha olefin blended with a nickel derivative of an alpha amino acid ofthe formula:

0 R-oH-ii-OH NITR where R and R are selected from the class ofsubstituted and unsubstituted alkyl, aryl and aralkyl residues, andhydrogen.

2. The composition of claim 1 wherein R is a C -C residue and R ishydrogen or a phenyl group.

3. The composition of claim 2 wherein the polymer is polypropylene.

4. The composition of claim 3 wherein the alpha amino acid is tyrosine.

5. The composition of claim 3 wherein the alpha amino acid is leucine.

6. The composition of claim 2 wherein the alpha amino acid is a-alanine.

7. The composition of claim 1 wherein the alpha amino acid is 2-phenylglycine.

No references cited.

JOSEPH L. SCHOFER, Primary Examiner. L. EDELMAN, Assistant Examiner,

1. A DYEABLE COMPOSITION OF MATTER COMPRISING A POLYMER OF A HYDROCARBONALPHA OLEFIN BLENDED WITH A NICKEL DERIVATIVE OF AN ALPHA AMINO ACID OFTHE FORMULA: